Catching apparatus and method for a rapier weaving machine

ABSTRACT

A catching device ( 1 ) for holding an inserted weft thread in a rapier weaving machine having at least one rapier ( 6 ), which is movable along a rapier track ( 6   a ), includes a holding channel ( 5 ) which can be mounted in a stationary manner on the rapier weaving machine in order to take up a thread end of the inserted weft thread ( 9 ) and to hold it. In addition, the catching device includes a deflection nozzle ( 3 ) which can be mounted in stationary manner on the rapier weaving machine in order to deflect the thread end of the inserted weft thread to the holding channel ( 5 ).

The invention relates to a catching device and to a method for theholding of an inserted weft thread in a rapier weaving machine inaccordance with the preamble of claims 1 and 5 and also to a rapierweaving machine having such a catching device or equipped to carry outsuch a method.

In customary rapier weaving machines the weft thread is inserted into ashed by means of a bringer rapier secured to a rapier rod or to aflexible band and is taken over at a transfer position in the middlepart of the shed by a taker rapier and conveyed further. The bringerrapier has the task of reliably taking up the presented weft thread, ofinserting the same into the shed and guiding it precisely to the takerrapier. The taker rapier has the task of conveying the weft threadfurther until it has reached a release position outside of the shed.Each of the rapiers includes a rapier head with a thread clamp in orderto fixedly clamp the weft thread during the weft insertion. In therelease position outside of the shed the thread clamp of the takerrapier is opened and the thread end which is fixedly clamped therein isreleased. In order that the weft thread remains stretched a catchselvage is normally provided in rapier weaving machines, which is closeddirectly after the weft insertion and still before the shed, as well asa suction nozzle or suction channel which takes up the thread end andholds it firmly.

A suction device for rapier weaving machines is disclosed in thedocument JP 09-059848 A which surrounds the weft thread at the arrivalside between the release position and the shed on three or four sidesand in which a suction groove is formed which is connected to a suctionsystem. In this way it is possible to suck in the released thread endfrom a plurality of directions and hold it firmly in the suction groove.

With coarse weft yarns the suction flow of customary suction devices andnozzles is not always however sufficient in order to firmly hold thethread end during the beat up of the reed, because the thread end ispicked up not until after the beat up of the reed by the suction deviceor nozzle and the beat up movement of the reed generates an air flowwhich draws the thread end behind the reed. In this arrangement, thedanger exists that the thread end is woven in behind the reed and thusthe shed can no longer be opened in the edge region. During the nextweft insertion the warp threads are then torn in the affected region bythe taker rapier.

The object of the invention is to make available a catching device and amethod for the holding of an inserted weft thread in a rapier weavingmachine, as well as a rapier weaving machine having such a catchingdevice or equipped to carry out such a method, by means of which evencoarse weft yarns can be reliably held after the insertion.

This object is satisfied in accordance with the invention by thecatching device defined in claim 1, by the method defined in claim 6 andby the rapier weaving machine defined in claim 10.

The catching device in accordance with the invention for the holding ofan inserted weft thread in a rapier weaving machine having at least onerapier which is movable along a rapier track includes a holding channelwhich can be mounted in stationary manner on the rapier weaving machinein order to take up a thread end of the inserted weft thread and to holdit. In addition the catching device includes a deflection nozzle whichcan be mounted in stationary manner on the rapier weaving machine, forexample a deflection nozzle with a cyclically pulsed blowing flow, inorder to deflect the thread end of the inserted weft thread to theholding channel. In an advantageous variant the holding channel isdesigned for the connection of a suction line.

In an advantageous embodiment the holding channel and the deflectionnozzle can be installed in the region of the rapier track, for exampleon opposite sides of the rapier track. I.e. the holding channel and thedeflection nozzle are so designed and/or the catching device is providedwith fastener elements in such a way that the holding channel and thedeflection nozzle can be installed in the region of the rapier track. Ina further advantageous embodiment the deflection nozzle can be soinstalled that its blowing flow is directed transverse to the rapiertrack. The deflection nozzle and the holding channel can beadvantageously mounted in such a way that the blowing flow of thedeflection nozzle is partly or fully taken up by the holding channel.

In the method of the invention for the holding of an inserted weftthread in a rapier weaving machine having a shed and at least onerapier, which inserts the weft thread along a rapier track into theshed, the inserted weft thread is released by the rapier and a threadend of the inserted weft thread is taken up and held by a holdingchannel which is arranged in stationary manner on the rapier weavingmachine. In addition, the thread end of the inserted weft thread isdeflected to the holding channel by means of a deflection nozzle whichis arranged in stationary manner on the rapier weaving machine. In anadvantageous variant the thread end of the inserted weft thread is heldin the holding channel by means of a blowing flow and/or suction flow.

In an advantageous embodiment of the method a blowing flow is generatedtransverse to the rapier track by means of the deflection nozzle. In afurther advantageous embodiment of the method the thread end of theinserted weft thread is blown into the holding channel and/or heldtherein by means of a blowing flow of the deflection nozzle.

Furthermore, the invention includes a rapier weaving machine having acatching device in accordance with one of the above describedembodiments or equipped to carry out a method in accordance with one ofthe above described embodiments.

The catching device, the method and the rapier weaving machine inaccordance with the present invention have the advantage that even withcoarser weft yarns the thread ends can no longer pass behind the reed.Thus, a better fabric quality can be achieved, especially with coarserweft yarns, than is possible on rapier weaving machines with customarycatching devices. Moreover, in comparison to rapier weaving machineswith customary catching devices, the downtimes of the rapier weavingmachines caused by break-downs can also be reduced. It is furthermoreadvantageous, thanks to the above-described catching device and theabove-described method, that the manufacturing costs and the energyconsumption and servicing costs can be reduced in comparison tocustomary catching devices for rapier weaving machines, because thesuction fan and the filter unit provided between the holding channel andthe suction fan can be made smaller or can be omitted altogether,because the generation of the directed blowing flow requires less energythan the generation of a broadly fanned out suction flow in the regionof the rapier track. At the same time the servicing costs for the filterunit can be respectively reduced or fully avoided.

The above description of embodiments merely serves as an example.Further advantageous embodiments can be seen from the dependent claimsand the drawing. Moreover, in the context of the present invention,individual features of the described illustrated embodiments andvariants can be combined with one another in order to form newembodiments.

The invention will be described in the following in more detail withreference to the embodiment and to the drawing. There are shown:

FIG. 1 an embodiment of a catching device in accordance with the presentinvention in a rapier weaving machine from above and

FIG. 2 a perspective view of the embodiment of FIG. 1.

The FIGS. 1 and 2 show an embodiment of a catching device in accordancewith the present invention in a rapier weaving machine from above and inperspective view, respectively. The rapier weaving machine includes atleast one rapier 6 which can, for example, as shown in FIG. 1 bedesigned as a taker rapier. The rapier shown in FIG. 1 is movable to andfro in the direction 6 a′ and on the rapier track 6 a in order to inserta weft thread 9 into a shed which is formed by warp threads 10, 10.1,10.2. For the guidance of the rapier 6 a rapier guide 2 can be provided.The rapier can, as shown in FIG. 1, be provided with a thread clamp inorder to fixedly clamp the weft thread during the weft insertion. FIG. 1shows a weft thread after the weft insertion, with the thread clampbeing opened in order to release the inserted weft thread. The catchingdevice 1 that is shown includes a holding channel 5 which is arranged instationary manner on the rapier weaving machine. It can, for example, besecured by means of a fastener element 7.2 to the rapier guide 2 inorder to take up and to hold the thread end of the inserted weft thread9. In addition the catching device that is shown includes a catchingnozzle 3 which is arranged in stationary manner on the rapier weavingmachine. It can, for example, be secured by means of fastener elements7.1, 7.1′, 7.1″ to the rapier guide 2. The catching nozzle 3 isadvantageously connected to a line 3 a in order to supply a blowingfluid. A blowing flow can be produced by means of the deflection nozzle3 in order to deflect the thread end of the inserted weft thread towardsthe holding channel 5. If required, the blowing flow can be pulsedcyclically.

In an advantageous embodiment the holding channel 5 and the deflectionnozzle 3 are installed, as shown in FIGS. 1 and 2 in the region of therapier track 6 a, for example on opposite sides of the rapier track. Ina further advantageous embodiment a blowing flow 4 transverse to therapier track 6 a can be generated by means of the deflection nozzle 3.

In an advantageous embodiment the thread end of the inserted weft threadis blown by means of the deflection nozzle 3 into an opening 5 a of theholding channel 5, for example in that the deflection nozzle and theholding channel are so mounted that the blowing flow of the deflectionnozzle is directed towards the holding channel and/or can be partly orwholly taken up by the holding channel. In a further advantageousvariant the holding channel 5 is designed for the connection of asuction line so that the thread end of the inserted weft thread can beconveyed by means of a blowing flow and/or suction flow into the opening5 a of the holding channel 5. Depending on the embodiment, the insertedweft thread can subsequently be held in the holding channel 5 by meansof the blowing flow and/or suction flow.

The rapier weaving machine can, as shown in FIGS. 1 and 2 be equippedwith a reed 8 in order to beat up the inserted weft thread 9 at a beatup edge 12. The thread end of the inserted weft thread is therebydeflected, as described above, by the blowing flow 4 of the deflectionnozzle 3, to the holding channel 5 so that the thread end cannot passbehind the reed during the beat up movement thereof. Thanks to thismeasure fabric faults are avoided which can arise through thread endswoven in behind the reed. In an advantageous variant the thread ends ofthe weft threads 9′, 9″, 9′″ which were woven in earlier remain in theholding channel 5 until they are drawn out of the holding channel by theadvance of the fabric 11 produced by the weaving process. The threadends which are drawn out of the holding channel are at this point intime so far removed from the reed 8 that no danger any longer existsthat they will be woven in.

An embodiment of the method of the invention for the holding of aninserted weft thread in a rapier weaving machine will be described inthe following with reference to FIGS. 1 and 2. In the embodiment therapier weaving machine includes at least one rapier 6 which is movedalong a rapier track 6 a for the insertion of the weft thread. Theinserted weft thread 9 is then released by the rapier and the thread endof the inserted weft thread is taken up and held by a holding channelarranged in stationary manner on the rapier weaving machine. In additionthe thread end of the inserted weft thread is deflected towards theholding channel 5 by means of a deflection nozzle 3 which is arranged instationary manner on the rapier weaving machine.

In an advantageous embodiment of the method a blowing flow 4 trans-verseto the rapier track 6 a is generated by means of the deflection nozzle3. In a further advantageous embodiment of the method the thread end ofthe inserted weft thread 9 is blown by means of the blowing flow 4 ofthe deflection nozzle 3 into the holding channel 5. In an advantageousvariant the thread end of the inserted weft thread 9 is held in theholding channel 5 by means of a blowing flow and/or suction flow.

Furthermore, the invention includes a rapier weaving machine having acatching device in accordance with one of the above-describedembodiments and/or equipped to carry out a method in accordance with theabove description.

The catching device and the method in accordance with the abovedescription are suitable for the holding of fine and coarse weft yarnsin rapier weaving machines. Thanks to the use of a deflection nozzle theenergy cost and the cost of servicing can be reduced relative tocustomary catching devices for rapier weaving machines which are simplyprovided with a suction channel.

1. A catching device for holding an inserted weft thread in a rapierweaving machine having at least one rapier (6) which is movable along arapier track (6 a), said catching device (1) including a holding channel(5) which can be mounted in a stationary manner on the rapier weavingmachine in order to take up a thread end of the inserted weft thread (9)and to hold it, characterized in that the catching device additionallyincludes a deflection nozzle (3) which can be mounted in stationarymanner on the rapier weaving machine, in particular a deflection nozzlehaving a cyclically pulsed blowing flow in order to deflect the threadend of the inserted weft thread to the holding channel (5).
 2. Acatching device in accordance with claim 1, wherein the holding channel(5) is designed for connection to a suction line.
 3. A catching devicein accordance with claim 1, including in addition fastener elements(7.1, 7.1′, 7.1″, 7.2) in order to mount the holding channel (5) and thedeflection nozzle (3) in the region of the rapier track (6 a) inparticular on opposite sides of the rapier track.
 4. A catching devicein accordance with claim 1, wherein the deflection nozzle (3) can bemounted so that a blowing flow (4) of the same is directed transverse tothe rapier track (6 a).
 5. A catching device in accordance with claim 1,wherein the deflection nozzle (3) and the holding channel (5) can bemounted in such a way that the blowing flow (4) of the deflection nozzleis partly or fully taken up by the holding channel.
 6. A method for theholding of an inserted weft thread in a rapier weaving machine having ashed and at least one rapier (6) which inserts the weft thread along arapier track (6 a) into the shed, in which method the inserted weftthread (9) is released by the rapier and a thread end of the insertedweft thread is taken up and held by a holding channel arranged in astationary manner on the rapier weaving machine, characterized inchannel arranged in a stationary manner on the rapier weaving machine,characterized in that the thread end of the inserted weft thread isdeflected to the holding channel (5) by means of a deflection nozzle (3)which is arranged in stationary manner on the rapier weaving machine. 7.A method in accordance with claim 6, in which a blowing flow (4)transverse to the rapier track (6 a) is produced by means of thedeflection nozzle (3).
 8. A method in accordance with claim 6, in whichthe thread end of the inserted weft thread (9) is blown by means of ablowing flow (4) of the deflection nozzle (3) into the holding channel(5).
 9. A method in accordance with claim 6, in which the thread end ofthe inserted weft thread (9) is held by means of a blowing flow and/orsuction flow in the holding channel (5).
 10. A rapier weaving machinecomprising a catching device in accordance with claim
 1. 11. A rapierweaving machine adapted to carry out a method in accordance with claim5.